1. Field of the Disclosure
The present disclosure relates to a high power fiber laser system having an integrated termination assembly. More specifically, the present disclosure relates to a fiber optic system having a termination block with an optimized angle of projection together with a reflector for creating total internal reflection and minimizing the coupling of back-reflected beams into the cladding of the fiber upstream from the block.
2. Description of the Related Art
The related art involves the use of high performance fiber optic fibers to deliver a light beam to the surface of a workpiece. Under some circumstances, these fibers terminate in a housing that may be water-cooled. The reflected radiation from the surface of the workpiece or other thermal absorption is accomplished by the water as is known to those of skill in the art. See for example, U.S. Pat. No. 6,167,177 which issued Dec. 26, 2000 to Sandstrom et al. Though these fibers may be designed for withstanding high levels of back-reflected light from the projected beam or other damage, known solutions to the back-reflection that re-enters the fiber housing may not be effective.
FIG. 1 illustrates an output fiber optic system 100 of high power fiber laser including a protective layer 115, which surrounds a delivery fiber 112 and at least one terminal connector, including conventional bulk optics 122 of conventional types known to those of skill in the art. Internally, the terminal block connector is configured with a cone termination block 114 spliced to the output end of delivery fiber 112. The fiber optic system 100 may be used for a variety of applications, such as cutting; welding; and other operations associated with a workpiece surface 118. During irradiation of workpiece surface 118 by output radiation 116, back reflected light 120 propagates backwards through bulk optics 122 into block 114 and, if not treated properly, may be damaging to system 100, as discussed further below.
Typically, block 114 has a cylindrical cross-section. To the detriment of laser fiber 100, when a portion of scattered back-reflected light 120 is incident on the surface of block 114, some of the light is coupled into a core 111 and some is coupled into a cladding 113 of fiber 112 and some of light is coupled directly to a protective layer 115. The damage of protective layer 115 by back reflected light inevitably leads to the complete destruction of at least the terminal part of the fiber laser system.
Accordingly, there is a need for an improved means for reducing or eliminating back-reflected light from entering the delivery portion of a fiber lager system and causing overheating of the fiber's protective polymeric coatings or protective cladding, and other structures, which would lead to damage of the system.